U.S. FOUNDRY & MANUFACTURING CORPORATION
MANHOLE RINGS & COVERS
M-3
Surface water infiltration is a serious problem in many areas and the cost of treating this water continues to increase
every year.
Tests performed by U.S. Foundry and an independent laboratory show that a conventional ring and cover with
machined seats can leak well over 200 gallons per hour. Actual seepage depends on the condition of the ring and
cover seat.
The U.S. Foundry “O” Ring Seal (ORS) and “T” Gasket (TGS) Covers can reduce water infiltration to near zero. These
castings allow access into manholes without having to remove bolts or gasket.
The patented “O” Ring Seal* used on both the “ORS” and “TGS” consists of a precise machined dovetail groove on the
manhole cover seat, which is fitted with a continuous dovetailed gasket. This design offers a gasket that will compress
seal with minimal abrasion to the gasket and is physically held in place without gluing. All new lids cast for ORS and
TGS application have a protective skirt to prevent damaging of the gasket during handling.
U.S. Foundry can also supply replacement covers for your existing manholes. Both the ORS and TGS application
can be installed on most covers and can be retrofitted into the existing rings creating a “sealed” manhole. Just give
U.S. Foundry Catalog Number and the ring seat dimensions, and we will let you know if your existing ring can receive
a U.S. Foundry “O” Ring Seal lid.
For extra security and water tightness, these applications can be used in conjunction with Wedgelocks, Adjustable
Camlocks or bolted with our standard watertight bolting process.
When considering Inflow Protectors, it should be noted that The “ORS” and “TGS” applications already reduce surface
infiltration to nearly zero so there is no need for an additional pan insert. If an insert will be used, then it is important to
identify the critical dimensions of both the ring and cover underside to insure proper fit. Inserts that seat between the
ring and cover will raise the cover and can create a tripping hazard. You should consult your sales or customer service
representative for assistance.
*
U.S. PATENT No. 4,828,274
ORS
TGS
USF “O” RING SEAL AND “T” GASKET APPLICATIONS